We estimate the GWP from EV production to be 87 to 95
grams carbon dioxide equivalent per kilometer (g CO2-eq/km),
which is roughly twice the 43 g CO2-eq/km associated with ICEV
production. Battery production contributes 35% to 41% of the EV
production phase GWP, whereas the electric engine contributes 7%
to 8%. Other powertrain components, notably inverters and the
passive battery cooling system with their high aluminum content,
contribute 16% to 18% of the embodied GWP of EVs.

In addition:

We find that EVs powered by the present European
electricity mix offer a 10% to 24% decrease in global warming
potential (GWP) relative to conventional diesel or gasoline
vehicles assuming lifetimes of 150,000 km. However, EVs exhibit
the potential for significant increases in human toxicity,
freshwater eco-toxicity, freshwater eutrophication, and metal
depletion impacts, largely emanating from the vehicle supply
chain.

The report already has re-ignited the usually loud and always cantankerous debate over whether electric vehicle design is better for the
environment, more virtuous or simply cooler. But a key take-away from the report is this line:

"(The finding) poses the question of how serious are
we about life cycle thinking, and how much control and oversight
we, customers, and policy makers believe should be exerted
across production chains.

We've expended a lot of effort and real and digital "ink" on the
issue of RoHS
in recent years. "RoHS-compliant" today is an almost mandatory
marketing badge.

Still:

To what extent is "design for environment"
baked into your organization, taking into consideration the the broader implications than toxic
metals in a landfill?

Does your company have as one of its guiding principles a design-for-environment principle?

PART 2
Today the U.S. consumes about 12 Mbbl/day of oil equivalent in natural gas. That’s about the daily consumption of oil for ground transportation. So, the U.S. already consumes huge quantities of NG. Furthermore, NG is less polluting. It seems almost counterintuitive, but the CO2 emissions of a natural gas hybrid vehicle would be less than that of an equivalent EV. Of course, that’s a hypothetical NG hybrid (with gasoline ICE replaced by CNG ICE) since to my knowledge none is on the market. This hypothetical NG hybrid need only have the average hybrid efficiency to achieve lower CO2 emissions than an EV. CO2 emissions from such a vehicle would be 10% less than an equivalent EV with today’s electric generation mix of 45% coal and 24% NG. CO2 emissions of such a vehicle in China would be 60% less. A NG hybrid would be cheaper than an EV (MSRP for a Prius $24K, Volt $39k). A NG hybrid would overcome the two major objections to NG vehicles. The first is range, but with almost double the efficiency due to hybrid technology, range would nearly double, making range equivalent to today’s gasoline powered vehicles. The second issue is reduction in acceleration performance, but a hybrid uses the electric motor for acceleration, not the ICE. Exploiting NG for ground transportation has many advantages: increase in jobs in natural gas industry, vehicle industry jobs, improvement in balance of payments, velocity of money gains from energy dollars remaining in U.S. economy, energy independence, energy security, reduce entanglements in Middle East, improved national security, reduced emissions. Moving to NG for ground transportation will give us the 30 years or so needed to resolve the issues with electrified ground transportation. So, focus on the micro issues of CO2 emissions from EV manufacturing misses the big issues of energy and the economy. As engineers we need to find solutions that work.

PART 1
CO2 emissions is only one of many factors, the most important of which is economic factors. The EV does not pass the economic test. On the other hand, there is a need for a replacement of oil as a ground transportation fuel. Even moderate oil experts, such as Charlie Maxwell, see oil production straining its limits over the next decade followed by slow decline. An IMF model (The Future of Oil: Geology versus Technology) forecasts oil not going below $100/bbl after 2013 (average case, best case after 2016). $100/bbl translates to about $400B annual cost for oil imports. Improving petroleum-fueled vehicle efficiency is not the answer. Finding a substitute for oil is the pragmatic solution. The EV provides such a substitute, but it is too expensive. The best candidate substitute for oil at this time is natural gas, of which the US has an abundant supply, at a price half that of oil (this is likely a short-term affect due to excess NG supply).

And this report is just coming out now?
It matters not, beause the electric vehicle is the vehicle of the near future until we can find a cleaner and more efficient method to propel vehicles.
As far as the battery materials, they are and will be in short supply so they will be efficiently recycled.
The motors that propel these cars also emit ozone, but in smaler quantities than a gasoline vehice.
Finally, the utimate choice for the "front-end" (charging current not generated by the regen brakes) to charge te vehicles will be topic of heated debate for decades. Would you like to use Coal, natural gas, biowaste, or star bulding new Nuclea Plants?

Ah, RoHS.
Lead in solder does not leach out into landfills, unlike lead in batteries. It is bound to the tin. On the other hand, requiring the use of non-lead solder means that we have to use higher temperatures during manufacturing (use more energy), use more heat resistant materials that can withstand these higher temperatures (using potentially more hazardous materials), and end up with more scrap (failures during manufacturing and reduced reliability due to increased heat of assembly and increased generation of tin-whiskers, even in the best of conditions).
So I'm not so sure RoHS is a good example to use for 'design for environment'. It is more of a 'design by committee' (a committee of politicians in Europe who don't always look too deeply at the all the side-effects when coming up with their rules).

There's far more than simply the amount of CO2 produced. The issue with vehicle emissions is that they get dumped directly in populated areas. In addition to that, coal is being slowly phased out, and there are more sources for electricity than just coal and natural gas.
In addition to that, it sounds as if the discussion of electricity use for aluminum production assumes that they're made from virgin aluminum from ore, which is very much electric intensive. However, I recall from elementary school that recycled aluminum uses only 5% of the electricity compared to the inputs required to separate the aluminum metal from the molten ore.